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Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter62 Configuring Active/Standby Failover
Information About Active/Standby Failover
Table62-2 shows the failover action for each failure event. For each failure event, the table shows the
failover policy (failover or no failover), the action taken by the active unit, the action taken by the
standby unit, and any special notes about the failover condition and actions.
Table62-2 Failover Behavior
Failure Event Policy Active Action Standby Action Notes
Active unit failed (power or
hardware)
Failover n/a Become active
Mark active as
failed
No hello messages are received on
any monitored interface or the
failover link.
Formerly active unit recovers No failover Become standby No action None.
Standby unit failed (power or
hardware)
No failover Mark standby as
failed
n/a When the standby unit is marked as
failed, then the active unit does not
attempt to fail over, even if the
interface failure threshold is
surpassed.
Failover link failed during
operation
No failover Mark failove r
interface as failed
Mark failover
interface as failed
You should restore the failover link
as soon as possible because the
unit cannot fail over to the standby
unit while the failover link is down.
Failover link failed at startup No failover Mark failover
interface as failed
Become active If the failover link is down at
startup, both units become active.
Stateful Failover link failed No failover No action No action State information becomes out of
date, and sessions are terminated if
a failover occurs.
Interface failure on active unit
above threshold
Failover Mark active as
failed
Become active None.
Interface failure on standby
unit above threshold
No failover No action Mark standby as
failed
When the standby unit is marked as
failed, then the active unit does not
attempt to fail over even if the
interface failure threshold is
surpassed.